atsb final report released 16 may 2013 - Ambulance Service of NSW

FINDINGSFrom the evidence available, the following findings are made with respect to thewinching accident that occurred 16 km west-south-west of Wollongong Airport,New South Wales on 24 December 2011 and involved Agusta WestlandAW139 helicopter, registered VH-SYZ. They should not be read as apportioningblame or liability to any particular organisation or individual.Contributing safety factors• The low light conditions prevented the air crewman from seeing the winchcable, affecting his assessment of the potential effect of the upwards movementof the helicopter while winching in the cable, and led to the patient and dutyparamedic being unintentionally pulled from the ledge.• The position of the helicopter at the time the patient and duty paramedic werepulled from the ledge, although necessary to ensure adequate hover reference inthe low light conditions, made their contact with the ground unavoidable, andresulted in the fatal injuries sustained by the duty paramedic.• The continued execution of the retrieval plan in dark conditions contributed tothe air crewman’s misperception of the amount of slack in the winch cable, andthe extent that the helicopter was displaced from the rock ledge.• The accepted use of procedural adaptation by special casualty access teamparamedics, and the past success of rescues that involved adapted techniques,probably led to the retrieval procedure that was used on the night. [Minor safetyissue]Other safety factors• The air crewman was unable to communicate with the paramedics via radio dueto a lack of familiarity with the helicopter’s radio system.• The planned retrieval procedure, utilising a stabilising rope system, was neitherdocumented nor trained for and the crew’s resulting low level of familiaritymade assessment of the associated risk difficult.• Ambulance rescue crewmen did not conduct any night winching recencytraining, resulting in an increased risk of unfamiliarity with night winchingprocedures and their associated hazards. [Minor safety issue]• The increased capability of helicopters and rescue winches enabled the conductof complex winch rescues beyond the current level of winch training andprocedural support associated with the traditional special casualty access teamclinical access role, leading to an increased risk that hazards associated withcomplex rescues were not identified. [Minor safety issue]• The helicopter’s lighting set-up did not allow independent control of thesearchlights by the pilot using the switches on the flight controls, as required bythe operations manual and Civil Aviation Order 29.11, and increased the risk ofthe loss of hover reference and distraction in the case of a single light failure orswitch mis-selecion by a pilot. [Minor safety issue]- 45 -